Dozens of mountain bikers in a race in Norway have fallen sick most likely due to spray from sheep droppings on their path, Norwegian media reported Wednesday.

Of the 300 cyclists who took part in the TransØsterdalen race at the end of June in southeastern Norway, at least 50 were struck with fever, stomach pain and diarrhoea in the days following the competition, according to public broadcaster NRK.

"This is most likely a Campylobacter infection," race doctor Tor Halvor Bjørnstad-Tuveng told NRK, referring to a bacteria which is present in the intestines of many animals.

He said material from the sheep droppings, which have decomposed during heavy rain and projected on the bikers' route, must have sprayed onto their bottles, faces and hands as they rode by.

"In particular, if the faeces are fresh and in large quantities," Bjørnstad-Tuveng said, "they can splatter on their bottles in such a way that they ingest it when they drink".

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